Panicum plant named ‘Cheyenne Sky’

ABSTRACT

The new and distinct cultivar of ornamental grass named  Panicum virgatum  ‘Cheyenne Sky’ with compact habit, erect culms and foliage and becoming concord-grape colored, suitable as a potted plant, for multi-seasonal interest mass or specimen landscaping, and for cut flower arrangements.

Botanical classification: Panicum virgatum.

Variety denomination: ‘Cheyenne Sky’.

BACKGROUND OF THE PLANT

Panicum virgatum ‘Cheyenne Sky’, hereinafter also referred to as‘Cheyenne Sky’ and the “new plant” is a new and distinct cultivar ofSwitch Grass. It was crossed by Gary M. Trucks in the summer of 2002between Panicum virgatum ‘Rostrahlbush’ (not patented)×Panicum virgatum‘Amber Wave’ (not patented) at a nursery in Benton Harbor, Mich. andselected for further observation in the summer of 2003.

SUMMARY OF THE PLANT

The plant has been successfully propagated by division at the sameperennial plant nursery in Benton Harbor, Mich. and found to produceidentical plants that maintain the unique characteristics of theoriginal plant. The plant is stable and reproduces true to type insuccessive generations of asexual reproduction.

‘Cheyenne Sky’ differs from its parents as well as all other Panicumknown to the applicant, in that the plant develops concord-purplecolored foliage, that is very upright. The new plant is shorter than‘Amber Wave’ and slightly taller than ‘Rostralbush’, but more uprightthan both cultivars. The most similar known Switch Grass cultivars are‘RR1’ U.S. Plant Pat. No. 17,944 (more commonly know as Panicum ‘RubyRibbons’) and ‘Prairie Fire’ U.S Plant Pat. No. 19,367. In comparison to‘Ruby Ribbons’ the new plant is taller, more upright in foliage habitand develops less red and more purple in the foliage. In comparison to‘Prairie Fire’ the new plant is shorter, more upright in foliage, andwith less gray mixed with purple in the foliage.

Comparison Table SEASON HEIGHT INITIAL SEASONAL OF CULTIVAR (cm) COLORCOLOR CHANGE HABIT ‘Cheyenne Sky’ 112 Blue Concord Early July Very greenpurple Upright ‘Haense Herms’ 100 Green Red purple Early Upright (notpatented) August ‘Prairie Fire’ 100 Blue Grayed Early July Upright greenpurple Upright ‘Rostrahlbush’ 110 Green Red purple Early Upright (notpatented) August ‘Ruby Ribbons’ 55 Blue Red purple Mid July Upright PPgreen ‘Shenandoah’ 140 Blue Red purple Late July arching (not patented)green

BRIEF DESCRIPTION OF THE DRAWINGS

The photographs of the new plant demonstrate the overall appearance ofthe plant, including the unique traits. The colors are as accurate asreasonably possible with color reproductions. Ambient light spectrum,source and direction may cause the appearance of minor variation incolor.

FIG. 1 shows the overall plant in mid-season.

FIG. 2 shows a close-up of the inflorescence in early to mid-August.

GENERAL DESCRIPTION OF THE PLANT

Panicum virgatum is native to all but the Pacific Coast states of theMainland United States in addition to parts of Canada and CentralAmerica. There are several selected cultivars in production or commerce.Panicum virgatum ‘Cheyenne Sky’ differs from all of these known to theinventor in that it has:

-   -   1. Blue green foliage that develops early in the season to a        concord purple.    -   2. Short compact habit with foliage very upright allowing        coloration to occur on both sides of foliage.

DETAILED BOTANICAL DESCRIPTION

The following descriptions and color references are based on the 2001edition of The Royal Horticultural Society Colour Chart except wherecommon dictionary terms are used. The new plant, ‘Cheyenne Sky’, has notbeen observed under all possible environments. The phenotype may varyslightly with different environmental conditions, such as temperature,light, fertility, moisture and maturity levels, but without any changein the genotype. The following observations and size descriptions are ofa four-year old plant in a trial garden in Benton Harbor, Mich. in fullsun with supplemental water and fertilizer.

-   Parentage: Controlled cross of Panicum virgatum ‘Rostrahlbush’    (female)×Panicum virgatum ‘Amber Wave’ (male).-   Propagation:    -   -   Method.—By division of the culms; Time to finishing in a 3.8            liter pot: three months; Rooting habit: normal, coarsely            branching.-   Plant description:    -   -   Plant shape and habit.—Hardy herbaceous perennial forming            tightly rhizomatous clump, with very upright culms topped            with finely textured airy inflorescence producing a narrow            clump taller than wide.        -   Plant size.—Foliage height at flowering is about 112 cm tall            from soil line to the top of the foliage; about 45 cm wide            at soil line and about 90 to 95 cm at widest point at the            flowers.-   Foliage description: Glabrous, with microscopic marginal dentations,    flat, alternate along culm, erect through tips, sheathed from node    of attachment to ligule, linear, deciduous but persist through    winter.    -   -   Foliage size.—25 to 32 cm long, shorter at distal end,            averaging 30 cm; 8 to 10 mm wide, averaging 9 mm.        -   Foliage color.—Adaxial surface early season and young            foliage: RHS 137A; Abaxial surface early season and young            foliage: closest to RHS 138A; Adaxial surface mid season and            later: nearest RHS N186B; Abaxial surface mid season and            later: mixtures of RHS 187A and RHS 183A with portions near            the culm of RHS N138B.        -   Veins.—Parallel; color same as the surrounding leaf on both            the top and bottom of the leaf.        -   Culm (stem).—Erect, cylindrical, 75% enclosed by leaf            sheath, about seven nodes per culm; about 120 per clump.        -   Culm dimension.—80 to 88 cm long without panicle; including            panicle between 105 and 115 cm long with average about 112            cm; about 3.0 mm diameter at base; internode length 15 to 22            cm.        -   Culm color.—Mixture of RHS N186C and RHS 137A with portions            4 mm above node nearest RHS 145C and 3 mm below node nearest            RHS 144C.        -   Node description.—About 7 per culm, between 3 to 4 mm            diameter and length 4 to 5 mm; closest to RHS 199B where            receiving full sun exposure, nearest RHS 199D where less            exposed.-   Flower description: Finely branched open panicle, one panicle per    culm.    -   -   Flower timing.—Beginning early August, flowering through            late August and panicles dry and remain effective through            winter; No fragrance detected.        -   Panicle.—Pyramidal, about 30 cm long and 25 cm wide; overall            effective color RHS 187A.        -   Rachis.—Branched, about 30 cm long and 1 mm at base;            starting RHS N138C and coloring up to RHS N187A.        -   Pedicel.—Thin, cylindrical, between 2 cm and 5 cm long and            less than 1 mm diameter, starting RHS N138C and coloring up            to RHS N187A.        -   Rachilla.—Thin, about 5 mm long and 0.2 mm diameter; color            starting RHS 137D and developing to RHS N187A.        -   Lower glume.—About 2.5 mm long and 1 mm wide; nearest RHS            187B.        -   Lemma.—Outer and inner — both about 3 mm long and 1.5 mm            wide, and RHS 187B on surfaces exposed to sun, RHS 145A in            areas minimally exposed to sun and RHS 157C areas protected            from sun.        -   Spikelet.—Usually with 2 flowers, 1.5 to 2.5 cm long and 2.5            mm wide.        -   Gynoecium.—Stigma — two, feathered, protruding 1 to 2 mm            from glume, RHS 59A.        -   Androecium.—Filaments — fine, hair-like, white, less than            0.1 mm diameter and up to 2.0 mm long, joined near            longitudinal middle of anther; Anthers: two 2.0 to 3.0 mm            long, 1.0 mm wide, nearest RHS N25A.        -   Pollen.—Round, less than 0.1 mm in diameter, nearly            transparent lighter than RHS 155D.        -   Fruit.—Caryopsis; 2 to 3 mm long and 1.5 mm wide, nearest            RHS 164C.-   Hardiness, pest and disease resistance: The plant grows best with    plenty of moisture and adequate drainage, but is able to tolerate    some drought when mature. Hardiness at least from USDA zone 4    through 9. Disease and pest resistance beyond what is typical of    that of other Switch Grasses has not been observed.

1. A new and distinct cultivar of ornamental grass plant, Panicumvirgatum ‘Cheyenne Sky’ as herein described and illustrated, withcompact habit, erect culms and foliage and becoming concord-grapecolored, suitable as a potted plant, for multi-seasonal garden interest,and for cut flower arrangements.